It is a bit difficult to tell, especially since the proposed tax bill for 2018 has yet to be passed, but you are looking at roughly $80,000 to $90,000 in federal income tax, assuming you are filing single and taking the standard deduction. Under 2017 tax law, you would owe about $95,000, but I would expect this amount to go down:
(1) Your non-capital gain income tax (alimony) should be somewhat less - increased standard deduction, and you will not lose your personal exemption as you would under current law.
(2) Your capital gains tax should be about the same, since the brackets and tax rates are unchanged as of right now.
(3) You would owe Alternative Minimum Tax in 2017 of about $6300. That will either be zero or greatly reduced in 2018.
(4) You will owe Net Investment Income Tax of about $11,400, assuming the new law does not change the calculation of this - and I haven't seen anything that indicates a change
To avoid an underpayment penalty, just make an estimated tax payment equal to 110% of your 2017 tax liability (it should be 100%, but go to 110% just to make sure).
